The New York startup’s platform sounds similar to Google App Engine — namely, it’s an environment to build, host and scale web applications in the cloud. It’s a big day for 10gen; not only did the company announce its funding, it also released its software development kit, and made its source code available through an open source license.

So why invest in 10gen? Google is a probably not the easiest competitor to take on, particularly when it comes to cloud computing. But 10gen has some real advantages, argues Union Square partner Albert Wenger. He says the company answers the call he made last September when he declared, “I want a new platform.” For one thing, Wenger presents a brief but compelling list of the App Engine’s shortcomings. Some of them are probably temporary (like the fact that App Engine is currently limited to Python), but others are harder to dismiss. If a company sees itself as a Google competitor, will it feel comfortable letting Google host its code? Since 10gen doesn’t have to protect other interests, developers can feel more comfortable trusting the startup with their code.